Did you know that dogs can use their cold, wet (and cute!) noses to detect sources of heat and thermal radiation?
This discovery, via a 2020 study in Sweden which challenged dogs to choose between a hot and cold object in a room, making it the second known mammal to possess this superpower. (The other is a vampire bat.)
And that’s not all a dog’s nose can do. Read on to discover six reasons why dog noses are some of nature’s most amazingly designed instruments, instruments whose power humans are now trying to recreate:
1. Dogs’ sense of smell is between 10,000 and 100,000 times stronger than that of humans. This power comes in part from the approximately 300 million olfactory receptors that dogs carry in their noses, compared to just 6 million in us. And the part of the canine brain that is dedicated to smells is 40 times larger than ours, proportionally speaking.
2. Dogs can constantly smell, even when inhaling and exhaling. In contrast, when a human smells an odor (sniffs a rose, for example), we inhale that odor and breathe in oxygen through the same passage. But if a dog smells the same flower, the air “splits into two different flow paths, one for smelling and one for breathing,” Brent Craven, a bioengineer at the State University of Pennsylvania who modeled canine olfaction anatomy using high-resolution MRIs, NOVA said.
Craven and his colleagues found that part of air dogs’ inspiration is fed into a specialized area at the back of the canine nose reserved for scent detection, while the rest continues to rush to the lungs. And when dogs exhale, that air escapes through the nasal slits in a unique aerodynamic pattern that also guides fresh air, creating a breathing cycle that continuously feeds the internal laboratory at the back of the canine nose with new material. In a study by the University of Osloa hunting dog sniffed continuously for a full 40 seconds, over 30 breath cycles!
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3. Dogs can wiggle their nostrils independently, which helps them determine the direction a smell is coming from. Humans can only move their nostrils simultaneously. (Try. We’ll wait.)
4. Dogs are excellent at interpreting all the information that comes through their noses in great detail. In her book “Inside of a Dog,” canine cognition researcher Alexandra Horowitz writes that humans could taste a teaspoon of sugar added to a cup of coffee. But a dog could detect the same teaspoon of sugar in a million gallons of water, enough to fill two Olympic-size swimming pools.
And to take the sugar metaphor a step further, “if we humans walk into a bakery, we can say ‘somebody’s baking a pie here,'” canine research specialist Lynne Engelbert told NOVA. . “A dog would walk in and say, ‘Oh, someone’s baking a pie here, and it has apples, butter, cinnamon, and nutmeg in it.
5. Dogs can connect a human to the scent they leave behind with exceptional accuracy and even help diagnose sick humans with a variety of illnesses. Forensic chemist Ken Furton, who has studied dog olfaction for more than 25 years, once blew up a car with colleagues and then had detector dogs pick up human scent from the resulting debris . The dogs were able to sniff out the small amount of shrapnel and correctly identify people who had contact with the bomb before the explosion 82% of the time.
More recently, Furton and his colleagues examined whether dogs could be trained to identify patients with COVID-19 and found they could do so with 97.5% accuracy. “I was shocked,” he told NOVA. And a 2019 study reported that humans’ best friends can detect cancer with an equally high accuracy rate of 97%.
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6. Dogs Can’t Just Identify Human Remains, They Can Sniff Out already cremated remains among other ashes. Dogs in the American West are now trained to search for the cremated remains of owners’ loved ones when those homes are lost to the region’s increasingly violent wildfires. The nonprofit Alta Heritage Foundation brings specially trained search dogs and archaeologists to the site of a house destroyed by fire, using canine colleagues to determine where the lost ashes could be buried, then techniques archaeological sites to extract them.
The ashes are often the only thing his clients want back from their homes, Alta Heritage founder Alex DeGeorgey told NOVA. Thus, being able to find the ashes of loved ones in the ashes of a house is both powerful and always surprising. “I’ve done this hundreds of times,” DeGeorgey says of retrieving cremation ashes, “and I still marvel that we’re able to do it.”